Effect of Levodopa on Postural Motor Learning in Parkinson Disease

The primary goal of this project is to gain a better understanding of whether and how levodopa (a common anti-Parkinson disease medication) alters postural motor learning in people with Parkinson disease. A secondary goal is to assess whether motor cortical excitability, measured via Transcranial magnetic stimulation, is related to postural motor learning.

Participants with Parkinson disease will complete between 50 and 100 postural perturbations (via support surface translations), ON and OFF their dopamine replacement therapy (i.e. levodopa). Adaptation of responses to these perturbations will be tracked. Participants will also undergo transcranial magnetic stimulation to capture cortical excitability of the brain (in particular the motor cortex). Cortical excitability will be correlated to adaptation of stepping (i.e. postural motor learning) ON and OFF levodopa. Investigators will also capture postural motor learning and cortical excitability in age-matched healthy adults.

Investigators hypothesize that dopamine will have a negative effect on postural motor learning, and the cortical excitability will be correlated to postural motor learning.

Study Overview

• Status: Completed
• Conditions: Parkinson Disease
• Intervention / Treatment: Behavioral: Postural perturbation

• Study Type: Observational
• Enrollment (Actual): 42

Contacts and Locations

Study Locations

• United States
  • Oregon
    • Portland, Oregon, United States, 97239
      • VA Portland Health Care System, Portland, OR
    • Portland, Oregon, United States, 97210
      • Oregon Health & Science University
  • Utah
    • Salt Lake City, Utah, United States, 84148
      • VA Salt Lake City Health Care System, Salt Lake City, UT

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Individuals with Parkinson Disease or age-matched healthy adults in the north west United States (Oregon and Washington state).

Description

Inclusion Criteria:

• Between 18 and 90 years of age.
• Individuals with Parkinson Disease
• Healthy adults age-matched to PD participants
• Participants with PD will be currently taking dopamine replacement (i.e. Levodopa)

Exclusion Criteria:

All subjects exclusion criteria:

• Deep brain stimulation
• Recent (within 6 months) orthopedic injuries influencing standing or balance
• Inability to stand independently

Transcranial magnetic stimulation exclusion criteria (for the subset of individuals taking part in the Transcranial Magnetic Stimulation portion of the study):

• History of epilepsy or currently taking any epileptic medication,
• History of seizures
• Family history of epilepsy or seizures

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Parkinsons disease; Individuals with Parkinsons disease	Behavioral: Postural perturbation; Participants will undergo between 50 and 100 postural perturbations (quick movements of the support surface) in multiple directions. These perturbations will be between 9 and 24cm, and between 18 and 56 cm/s depending on participant tolerance.
Control; Age-matched healthy adults	Behavioral: Postural perturbation; Participants will undergo between 50 and 100 postural perturbations (quick movements of the support surface) in multiple directions. These perturbations will be between 9 and 24cm, and between 18 and 56 cm/s depending on participant tolerance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Movement of Center of Mass (COM) After Postural Perturbation	Investigators will assess (via automated and custom Matlab software) the magnitude of COM movement after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later).	Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication
Change in Steps After Postural Perturbation	Investigators will assess (via automated and custom Matlab software) the number of steps taken after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later).	Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in First Step Length	Investigators will assess (via automated and custom Matlab software) the length of the first step after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later).	Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication
Cortical Excitability	Investigators will assess the cortical excitability of the primary motor cortex in a subset of participants both ON and OFF levodopa. Specifically, we used transcranial magnetic stimulation to stimulate the motor cortex, where we measure muscular activity of the arm (i.e. motor evoked potentials; MEPs). The primary outcome variable noted below is the lowest stimulation setting (measured as a percentage) which results in an MEP in 5 of 10 trials.	TMS data was collected ON and OFF medication during one visit. This visit occurred within 3 weeks of the initial postural control assessments.

Collaborators and Investigators

• Sponsor: VA Office of Research and Development
• Collaborators: Oregon Health and Science University
• Investigators: Principal Investigator: Daniel S Peterson, PhD MS BS, VA Salt Lake City Health Care System, Salt Lake City, UT

Study record dates

Study Major Dates

• Study Start: August 1, 2014
• Primary Completion (Actual): January 1, 2016
• Study Completion (Actual): September 1, 2016

Study Registration Dates

• First Submitted: September 2, 2014
• First Submitted That Met QC Criteria: September 11, 2014
• First Posted (Estimate): September 15, 2014

Study Record Updates

• Last Update Posted (Actual): February 23, 2017
• Last Update Submitted That Met QC Criteria: January 4, 2017
• Last Verified: January 1, 2017

More Information

Terms related to this study

• Keywords: Parkinson Disease; Dopamine; Learning; Posture Balance
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Parkinsonian Disorders; Basal Ganglia Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases; Parkinson Disease
• Other Study ID Numbers: N1480-M

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No